[TSan] Improve support for running TSan test suite with GCC-TSan.

Test results with GCC-4.9.0: 78 expected passes, 74 unexpected failures.

llvm-svn: 209014

compiler-rt/test/tsan/lit.cfg

@@ -22,14 +22,18 @@ tsan_options = "atexit_sleep_ms=0"
 
 config.environment['TSAN_OPTIONS'] = tsan_options
 
+# GCC driver doesn't add necessary compile/link flags with -fsanitize=thread.
+if config.compiler_id == 'GNU':
+  extra_cflags = ["-fPIE", "-lpthread", "-ldl", "-lstdc++", "-lrt", "-pie"]
+else:
+  extra_cflags = []
+
 # Setup default compiler flags used with -fsanitize=thread option.
 # FIXME: Review the set of required flags and check if it can be reduced.
 clang_tsan_cflags = ["-fsanitize=thread",
                      "-g",
                      "-Wall",
-                     "-lpthread",
-                     "-ldl",
-                     "-m64"]
+                     "-m64"] + extra_cflags
 clang_tsan_cxxflags = config.cxx_mode_flags + clang_tsan_cflags
 # Add additional flags if we're using instrumented libc++.
 if config.has_libcxx: